The contribution of taxes, subsidies, and regulations to British electricity decarbonization

Great Britain’s carbon emissions from electricity generation fell two-thirds between 2012 and 2019, providing an important example for other nations. This rapid transition was driven by a complex interplay of policies and events: subsidized investment in renewable generation, regulation-driven closure of coal power stations, rising carbon prices, and energy efficiency measures. Previous studies ignore the interactions of these simultaneous measures with each other and with exogenous changes to fuel prices and the weather. Here, we use Shapley values—a concept from game theory—to disentangle these and precisely attribute outcomes (changes to CO2 emissions, electricity prices, and fossil fuel consumption) to individual drivers. We find the effectiveness of each driver remained stable despite the broad transformation of the power system. The four main drivers each saved 19–29 MtCO2 per year in 2019, reinforcing the view that there is no “silver bullet” and that a multi-faceted approach to deep decarbonization is essential.